The present invention pertains to integral skin rigid polyurethane structural foam compositions. More particularly, the present invention relates to the preparation of integral skin rigid polyurethane structural foam which contains polyether polyol, polyester polyol, an organic polyisocyanate and a chain extender. 2. Description of the Prior Art
The use of triisopropanolamine in combination with alkylene oxide adducts of aliphatic and aromatic amines has been disclosed in the prior art. U.S. Pat. No. 4,588,803 teaches the preparation of low shrinkage polyurethane sealant compositions employing among other reactants ethylene oxide adducts of toluenediamine and triisopropanolamine. U.S. Pat. No. 4,605,725 teaches the preparation of polyurethane sealant compositions employing alkylene oxide adducts of monoethanolamine in the presence of triisopropanolamine.